Depends on the corporation. The tech industry tends to be pretty good about using patents defensively, but there are notable exceptions. For example, Akamai has built a reputation of suing every new startup that enters the CDN space for patent infringement (Limelight, Speedera, Cotendo, etc). Ask any VC in the valley to fund your CDN biz and they'll ask you what your patent portfolio looks like and how big of a war chest you're building to fight the inevitable lawsuits.